Heat exchanging system for internal combustion engine

ABSTRACT

A heat exchanging system for an internal combustion system is disclosed herein. The heat exchanging system includes a pusher fan assembly, positioned between the internal combustion engine and a radiator. The pusher fan assembly enables air-flow towards the radiator. The pusher fan assembly includes a central hub, a plurality of blades, and a nose. The blades include a first end coupled to the central hub and a second end extending radially outwards from the central hub. The nose includes a base portion and a contoured outer portion. The base portion has a radius, R. The contoured outer portion has a maximum length, L dimension along axis of rotation. The contoured outer portion has an angular profile, ρ defined by formula ρ=(R*R+L*L)/2*R.

TECHNICAL FIELD

The present disclosure relates to a heat exchanging system for an internal combustion engine.

BACKGROUND

Various power units employed today include internal combustion engines for running various applications. Heat exchanging systems are provided for internal combustion engines so as to impart desired cooling and prevent over heating (which may result in low operational efficiency).

Internal combustion engines may be liquid cooled. In a liquid cooled internal combustion engine, an engine coolant circulates through jackets in an engine cylinder block and a cylinder head to extract heat from within. Upon exiting the internal combustion engine, the engine coolant passes through a radiator to exchange heat with passing air before it is re-circulated back into the engine. Generally, a fan is utilized to encourage air flow towards the radiator to assist heat transfer and thus lower the temperature of the fluid in the radiator. Whilst conventional fans may be effective in pushing air towards the radiator, it is found that there is a reduced amount of air flow in a central region of the radiator that is aligned with the fan.

SUMMARY OF THE DISCLOSURE

Various aspects of the present disclosure are directed to a heat exchanging system for an internal combustion engine. The heat exchanging system includes a radiator and a pusher fan assembly. The radiator includes a central portion and an outer portion. The pusher fan assembly is positioned between the radiator and the internal combustion engine so as to enable air to be pushed towards the radiator. The pusher fan assembly has an axis of rotation X-X aligned with the central portion of the radiator. The pusher fan assembly includes a central hub, a plurality of blades, and a nose. The central hub is located centrally with respect to the axis of rotation. Each of the plurality of blades has a first end coupled to the central hub and a second end extended radially outwards from the axis of rotation. The nose is rotatable with the central hub and the plurality of blades, with respect to the axis of rotation. The nose includes a base portion and a contoured outer portion. The base portion is coupled to the central hub and located centrally with respect to the axis of rotation. The base portion has a radius, R. The contoured outer portion extends from the base portion away from the central hub in a direction substantially along the axis of rotation and towards the radiator, such that the contoured outer portion defines a maximum Length, L dimension of the nose. The contoured outer portion has an angular profile, ρ defined by the formula, ρ=(R*R+L*L)/2*R.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a heat exchanging system having a pusher fan assembly with a nose positioned relative to a radiator;

FIG. 2 is a partial cross-sectional view of the nose shown in FIG. 1;

FIG. 3 is a front view of the radiator in use without the nose attached to the pusher fan assembly and shows a first air velocity gradient (by way of concentric ovals) of air being pushed through the radiator; and

FIG. 4 is a front view of the heat exchanging system of FIG. 1, showing the radiator in use with the nose attached to the pusher fan assembly and shows a second air velocity gradient (by way of concentric ovals) of air being pushed through the radiator.

DETAILED DESCRIPTION

Referring to FIG. 1, shown is a side view of a power unit 100 that may generate power for a multitude of purposes, including powering equipment or running a machine. Examples of machines that may be powered by the power unit 100 include, but are not limited to, vehicles, generators, rock crushers, irrigation pumps, and/or compressors. The power unit 100 may include an internal combustion engine 102 for power generation, and a heat exchanging system 104 for cooling the internal combustion engine 102.

The heat exchanging system 104 may include a radiator 106, a pusher fan assembly 108, a first radiator hose pipe 110, and a second radiator hose pipe 112. Both the first and the second radiator hose pipe 110 and 112, may facilitate a fluid communication between the radiator 106 and the internal combustion engine 102. More particularly, the first radiator hose pipe 110 may aid a hot coolant flow from the internal combustion engine 102 to the radiator 106, while a second radiator hose pipe 112 may facilitate the return of coolant, which is at a lower temperature to the internal combustion engine 102. This arrangement may provide a closed circulation passage for an engine coolant to impart continuous cooling. The coolant can be a mixture of water with anti-freeze or can be any other engine coolant as is customary. A thermostatically controlled bypass valve (not shown) may be employed to redirect a portion of hot coolant coming out of the engine head directly to the inlet pump (not shown) of coolant, as required, based on temperature of coolant upstream of the bypass valve.

The hot coolant downstream of the bypass valve directed towards the radiator 106 passes through a lengthy coil (not shown) running through the radiator 106. The circuit path of the coil may vary and may depend on amount of heat needed to be dissipated. In an exemplary embodiment, the coolant while passing through the coil may transfer heat to the coil by conduction and the coil, in turn, may transfer the heat to the surrounding air through convection carried out by air (generated by the fan) passing over the coil. The radiator 106 is positioned to receive an air flow from the pusher fan assembly 108 and includes a central portion 114 and an outer portion 116 that are subjected to different air flow patterns.

The pusher fan assembly 108 is positioned between the internal combustion engine 102 and the radiator 106. The pusher fan assembly 108 may be a mechanical unit driven by the internal combustion engine 102, a hydraulically driven unit independently driven, an electrically powered fan unit or any other alternative known to those having ordinary skill in the art. The pusher fan assembly 108 rotates about an axis of rotation X-X. The axis of rotation X-X is aligned with the central portion 114 of radiator 106. As the pusher fan assembly 108 rotates about the axis of rotation X-X, it collects the surrounding air and pushes towards the radiator 106. The pusher fan assembly 108 may provide forced convective cooling directed to the radiator 106 by encouraging heat transfer from the radiator 106 to the surrounding air. The amount of air pushed toward the radiator 106 may be a function of rotational speed of the pusher fan assembly 108. Further, the pusher fan assembly 108 includes a spindle 118, a flat disc-shaped central hub 120, a plurality of blades 122, and a nose 124.

The spindle 118 may be rotatably connected to a crankshaft (not shown) or may be pulley driven via a fan belt as is customary, based on any one of a variety of engine-driven output pulleys (not shown) which may be mounted typically on the front of the internal combustion engine 102. The central hub 120 attaches to the end of the spindle 118.

Referring again to FIG. 1, the central hub 120 is aligned centrally with the axis of rotation X-X, and provides a mounting base for a blade assembly or each of the blades 122 and the nose 124. The central hub 120 has a first side 126 with a nose attachment portion 128, and a second side 130 with a blade attachment portion 132. Each of the blades 122 has a first end 134, attached to the blade attachment portion 132 of the central hub 120. The first end 134 is attached to the blade attachment portion 132 of the central hub 120 by known fastening means, such as, but not limited to bolting, riveting, and welding. A second end 136 of each of the blades 122 extends radially from the axis of rotation X-X. The nose 124 will be discussed in detailed below.

The nose 124 includes a base portion 138, and a contoured outer portion 140. The base portion 138 is located centrally with respect to the axis of rotation X-X and is attached to the nose attachment portion 128 of the central hub 120. The base portion 138 is circularly shaped, with radius, R, as best shown in FIG. 2.

Referring to FIG. 2, shown is a profile of the contoured outer portion 140, which extends from the base portion 138 towards the radiator 106. The contoured outer portion 140 extends from the base portion 138 in a direction away from the central hub 120, and towards the radiator 106. The contoured outer portion 140 extends substantially along the axis of rotation, X-X. The contoured outer portion 140 has a maximum length dimension, L, relative to the base portion 138, extending along the axis of rotation X-X, towards the radiator 106. The contoured outer portion 140 has an angular profile, ρ, which is defined by the formula ρ=(R*R+L*L)/2*R. The angular profile ρ of the contoured outer portion 140 may be selected based on the application and amount of air flow desired toward the central portion 114. In an exemplary embodiment, the values for the coordinates of angular profile are: radius, R=60 millimeter, and length, L=90 millimeter, which results in the angular profile, ρ=97.5 millimeter for the contoured outer portion 140.

Referring to FIG. 3, there is shown a sample region 302 illustrating a first air velocity gradient through a radiator 106 when no nose 124 is present in a pusher fan assembly 108. The first air velocity gradient is depicted by spaced concentric ovals to represent the velocity gradient of air impinging on the radiator 106 as air is directed by the pusher fan assembly 108 (when no nose 124 is being used). Few distanced ovals illustrate a generally small air velocity impinging on the radiator 106 within the sample region 302 whereas a greater amount of ovals would illustrate a higher air velocity. In conventional pusher fan assemblies, the flow of air is directed predominantly towards the outer portion 116 of the radiator 106 (FIG. 1). This causes a reduced flow of air through the central portion 114 of the radiator 106, as shown by few, spaced oval portions.

Referring to FIG. 4, there is shown another sample region 304, but this time showing a second air velocity gradient through the radiator 106 when a nose 124 is present in the pusher fan assembly 108. In this example, a higher number of concentric ovals are present in the sample region 304 compared with the similar sized sample region 302 of FIG. 3. This represents the relative higher velocity gradient of air impinging on the radiator 106 as air is directed by the pusher fan assembly 108 (FIG. 1). The general intensity of the velocity is depicted by the ovals therefore the tightly nested ovals illustrate a greater and more intense amount of air velocity impinging on the radiator 106 within the sample region 304. Referring to FIG. 1, flow arrows 125 depict the air flow from pusher fan assembly 108 through the central portion 114 of the radiator 106 whereas flow arrows 127 depict air flow through the outer portion 116 of the radiator 106.

INDUSTRIAL APPLICABILITY

In operation, the engine coolant may be continuously circulated through the internal combustion engine 102 and the radiator 106 via a fluid pump (not shown). The engine coolant carries heat away from the internal combustion engine 102 and the temperature of the heated coolant is reduced when the coolant is circulated through the radiator 106 and the radiator 106 is subjected to the air being directed towards the radiator 106 via the pusher fan assembly 108.

The pusher fan assembly 108 rotates about the axis of rotation X-X, enabling an air flow towards the radiator 106, thereby enabling heat transfer from the engine coolant to the environment via the radiator 106 and air flow. As air flows towards the radiator 106, the nose 124 including the nose attachment portion 128 with contoured outer portion 140 draws air toward the central portion 114 of the radiator 106 and reduces the turbulence in the vicinity of the nose 124 and central portion 114. As a result, the air flow through the central portion 114 of the radiator 106 is substantially increased (compared with the scenario where no nose 124 is used). This, in turn, increases the cooling effect (heat transfer) at the central portion 114 of the radiator 106 and therefore substantially improves the overall cooling performance of the pusher fan-radiator combination. 

What is claimed is:
 1. A heat exchanging system for an internal combustion engine, comprising: a radiator having a central portion and an outer portion; a pusher fan assembly positioned between the radiator and the internal combustion engine so as to enable air to be pushed towards the radiator, the pusher fan assembly having an axis of rotation aligned with the central portion of the radiator, wherein the pusher fan assembly includes: a central hub located centrally with respect to the axis of rotation; a plurality of blades, each of the plurality of blades having a first end coupled to the central hub and a second end extended radially outward from the axis of rotation; and a nose being rotatable with the central hub and the plurality of blades with respect to the axis of rotation, the nose comprising: a base portion being coupled to the central hub and located centrally with respect to the axis of rotation, the base portion having a radius, R; and a contoured outer portion extending from the base portion away from the central hub in a direction substantially along the axis of rotation and towards the radiator such that the contoured outer portion defines a maximum Length, L dimension of the nose; wherein the contoured outer portion has an angular profile, ρ defined by the formula, ρ=(R*R+L*L)/2*R. 